There is no universawwy accepted mechanism of action for racetams. Racetams generawwy show negwigibwe affinity for common centraw nervous system receptors, but moduwation of centraw neurotransmitters, incwuding acetywchowine and gwutamate, has been reported. Awdough aniracetam and nebracetam show affinity for muscarinic receptors, onwy nefiracetam demonstrates nanomowar interactions. Modification of membrane-wocated mechanisms of centraw signaw transduction is anoder hypodesis.[2]